Unless the NBA goes for a 4th referee, one that does nothing but sit on the sideline and watch the video feed of the game, flopping can not be handled by the refs.
The only way flops can be addressed by refs is if after a flop occurs and a foul called while there is a slight stoppage in game play and that 4th referee can review the video and overturn the call almost immediately.
That's it. That's the only way. The game is too fast for most of these older than 50 years old referees to be able to distinguish between a flop and a foul on a regular and precise basis. The players are too fast, the game too fast and the players too skilled at getting real close to a player and flopping and making it appear as if they were fouled. Instant video replay without sacrificing length of game is the only way to do it.